抄録
The corrosion behavior of iron, cobalt, titanium, zirconium, nickel and chromium in molten V205 was investigated. The main results obtained are as follows:
1) At the initial stage, the oxidation of iron and cobalt obeys the linear rate law. In the next stage, the oxidation is accelerated and then retarded at the final stage.
2) The linear relationship at the initial stage implies that the oxidation reaction is diffusion controlled process.
3) It is considered that the oxidation rate should be affected by composition of the melt which changes with progress of the oxidation.
The oxidation rates of metals M in V2O5-MO melts were examined, and it was concluded that a) the oxidation rates of iron and cobalt are maximum at the eutectic composition, b) the oxidation rate of zirconium is less affected by the addition of ZrO2 in V2O5 melt, and c) as for nickel, the rate is retarded by adding NiO in V2O5 melt.
4) The causes of the accelerated oxidation can be suggested to be 1) the increase of the oxidation rate and the enhancement of convection in the melt due to the increased temperature by exothermic oxidation reaction of the metal, 2) the increase of concentration of oxidizing agent in V205-M0 melt caused by the dissolved metal oxide, MO.
